The demand for smaller and more sophisticated electronic appliances has resulted in semiconductor devices (semiconductor chips) such as ICs and LSIs used in such appliances having a higher level of integration and an increased capacity. There are also demands for packages of semiconductor chips to be smaller (thinner), include more pins, and have a higher density. To meet these demands, a system in package (SiP), in which a plurality of semiconductor chips are mounted on the same substrate, has been developed. For example, a SiP implementing a three-dimensional mounting technique for stacking semiconductor chips in a three-dimensional manner, namely, a chip-stacked package, has become popular. Such a chip-stacked package allows for high integration. In addition, since the wiring length may be reduced, circuits may operate at a higher speed and stray capacitance in wires may be reduced.
A known three-dimensional mounting technique manufactures a chip-stacked package by stacking a plurality of semiconductor chips onto a substrate and electrically connecting electrodes of the semiconductor chips to electrodes on the substrate with wire-bonded wires. However, in such a configuration in which the semiconductor chips are electrically connected to the substrate by wires, the wires are fine and thus increase the impedance. As a result, such a configuration cannot be applied to high-speed semiconductor chips. Further, there would be a need to provide a region for a wire loop in the package thereby enlarging the package in size.
Another known three-dimensional mounting technique manufactures a chip-stacked package by stacking a plurality of semiconductor chips that include through electrodes onto a substrate and electrically connecting the semiconductor chips to one another with the through electrodes (refer to, for example, Japanese Laid-Open Patent Publication No. 2006-179562). This technique allows for the wiring length to be decreased as compared to wire bonding thereby allowing for the package to be further reduced in size.